Smoke and vapor collecting hood



United States Patent Inventor Germain Courchesne 167 Chemin du Golf,Drummondville, Quebec, Canada Appl. No. 734,072

Filed June 3, 1968 Patented Sept. 29, 1970 SMOKE AND VAPOR COLLECTINGHOOD 6 Claims, 10 Drawing Figs.

U.S. Cl. .1 98/115, 1 26/300 Int. Cl .1 F23j 11/00 Field of Search 98/115 115K, I ISLH: 126/299, 300

[56] References Cited UNITED STATES PATENTS 3,292,525 12/1966 Jensen98/1 15(K1UX 3,340,788 9/1967 Ladinham 98/115(LH)UX 3.400549 9/1968Jensen 98/115(K)UX 3,411,428 11/1968 Ahlrich 98/115 PrimaryExaminer-Meyer Perlin An0rney- Pierre Lesperancc ABSTRACT: A smoke andvapor collecting hood provided with means to produce a flow of air inthe vicinity of and directed towards said hood to assist in theentrainment into the hood of smoke and vapors which might have otherwiseescaped the hood, the air flow being supplied by outside and inside airin adjustable proportion to be able to maintain a comfortabletemperature in the room in which the hood is located and prevent wasteofexpensive heated air.

Patented Sept. 29, 1970 Sheet 1 0:4

I Vin/T01? 69mm 0;, mum/Esme Patented Sept. 29, 1970 Z of 4 SheetPgtented Sept. 29, 1970 Shoot IIVVEAITOR F. N 5% m M m mw 0 an PatentedSept. 29, 1970 Sheet 1 of 4 larva-Arron Germ air COURt/f/[SNE SMOKE ANDVAPOR COLLECTING HOOD The present invention relates to hoods forcollecting smoke and vapors and, more particularly, to hoods used incommercial or home kitchens and to hoods used in industry for collectingvapors and smoke, for instance, produced during welding and other smokeand/or vapor producing operations.

It is known to provide hoods of the character described with means toprovide an additional air flow directed towards the inside of the hood,which greatly enhances the smoke and vapor collecting capacity of a hoodrelative to its size; if the air required for such a system is admittedfrom the outside, the room in which the hood is located will be undulycooled in cold weather; if inside air only is supplied to the system,expensive heated air will be wasted because exhausted to the exterioralong with the fumes.

The general object of the invention resides in the provision of a hoodof the character described, in which additional air is supplied to thehood by an air mixer and recirculator having an outside intake and aninside intake so arranged as to supply sufficient fresh air combinedwith inside air, so as to not unduly cool the room in which the hood islocated in cold weather while conserving heated inside air.

Another object of the invention resides in the provision of a hood ofthe character described, especially designed for use in association withwelding tables and the like, and provided with means to suck in thesmoke and vapors as much as possible at the level of the table itself.

Another object of the invention resides in the provision ofa hood of thecharacter described, provided with deflector means for the orificessupplying the additional air, which can be adjusted at any angle so asto direct the additional air flow in the desired direction.

The foregoing and other objects of the present invention will becomemore apparent during the following disclosure and by referring to thedrawings, in which:

FIG. 1 is a cross section through the hood at the level of one of theexhaust ducts, this hood being used in combination with a welding table;

FIG. 2 is a cross section of the embodiment of FIG. 1, but at the levelof the air supply for the hood;

FIG. 3 is a front elevation of the embodiment of FIG. 1 showing portionscut away and in section;

FIG. 4 is a front elevation, on a smaller scale, of a wall mounted hoodin association with a welding table;

FIG. 5 is a cross section of the embodiment of FIG. 4, the section beingtaken through the exhaust duct for the hood;

FIG. 6, shown on the first sheet of drawings, is a partial longitudinalsection ofa duct for supplying additional air;

FIG. 7 is a partial schematic view of a central hood provided withfilters for use in a commercial kitchen;

FIG. 8 is a schematic view of a wall-type commercial kitchen hoodprovided with filter means;

FIG. 9 is a cross section on line 9-9 of FIG. 10 of the arrangement of acommercial kitchen provided with additional air supply means inaccordance with the invention associated with a wall-type conventionalexhaust hood; and

FIG. 10 is a partial elevation of the arrangement of FIG. 9.

In the drawings, like reference characters indicate like elementsthroughout.

Referring to the first embodiment shown in FIGS. 1, 2. 3, and 4, hood 1is of generally rectangular shape and forms a top 2 and depending sides3 on all edges of the top.

It is supported by means not shown over a work table 4, for instanceused by welders. The top and sides of the hood are of double wallformation to provide air passages 5 and 6 respectively. The sides 3 areformed as assembled units and secured to the edges of the top 2 and thepassage 5 of the top 2 is in communication with the passages 6 of thesides 3 by means of holes 7, shown in FIGS. 4, made in the inner wall ofthe side 3 at the level of the air passage 5.

The inner wall of each side 3 is provided near its lower closed end withslit 8 defined by inturned lips 9 forming an air discharge alongsubstantially the entire inner periphery of the hood and directedtowards the center ofthe hood.

In front of each slit 8, is pivotally mounted on end brackets 10 securedto the inner wall of the sides 3, an air deflector, of baffle 11, soarranged that it can be adjusted to any angle and can make a completeturn about its axis.

The air deflectors 11 preferably have oppositely inclined longitudinalmarginal portions 12.

An exhaust duct 13 is in communication with the inside of the hood neareach end thereof. Exhaust ducts 13 extend through the double wall top 2of the hood and pass through a hole made in the exterior wall 14 of thebuilding in which the hood is located, being in communication with anexhaust chamber 15 in which is located motor-operated exhaust fan 16.

The outlet of chamber 15 is preferably provided with a conventionallouver system 17 arranged to close when the exhaust fan is not inoperation.

Referring to FIGS. 2 and 4, an air supply duct 18 is in communicationwith the inside of the double wall top 2 at the centre of the hood tosupply air to the slits 8 through air passages 5 and 6.

The duct 18 is in communication with a chamber 19 mounted in the wall 14and extending partially outside and inside thereof. Chamber 19 containsan air blower unit 20 having its discharge connected to duct 18 andoperated by an electric motor 21, itself mounted on a pivoted bracket 22adjustable by screw 23, so as to adjustably tighten the driving belt 24connecting the motor to the air blower.

Chamber 19 has a fresh air intake opening 25 which can be completelyclosed by a louver system 26 when there is no suction in chamber 19, thelouvers 26 closing under the action of gravity and opening when suctionis produced by the air blower 20 within chamber 19.

Said chamber 19 has an additional air intake 27, which opens within theroom in which the hood is located. Within intake 27 are arranged louvers28 pivotally connected at their center to chamber 19 and at their endsto a common actuating bar 30.

Louvers 28 alternate with stationary baffles 31. Common bar 30 is urgedupwardly by a tension spring 32, attached thereto and to the chamber 19into an upper position in which the louvers 28 are at an anglecompletely closing the intake 27. Bar 30 can be pulled downwardly bymeans of a rope or chain 33, which is attached by suitable means so asto adjust the angular position of the louvers 28.

Intake 27 may be connected to a duct, not shown, which may open near theceiling of the room in which the hood is located, if so desired.

Work table 4 is provided with a central upstanding partition 35terminating at a distance from the lower wall of top 2, but at a higherlevel than the lower end ofthe hood sides 3.

On each side of the partition 35 are located slightly upwardly divergingperforated panels 36, for instance made of asbestos cement. Partition 35and the two panels 36 are supported on the work table by a bracket 37.Perforated panels 36 are lined at their upper edges by edgings 38.Louvers 39, pivoted at their center on a shaft 40 carried by the sidesof the hood, extend along the entire length of the hood and are adjustably pivotable so as to close or open to the desired extent openings41 defined by the edgings 38 and angle irons 42 secured to the bottom ofthe hood top 2 and extending longitudinally of the same.

The hood arrangement in accordance with this first embodiment operatesas follows: the hood operates in a conventional manner with the louvers39 being open, the exhaust fan 16 operating and the air blower 20 beingstopped. However, when the latter is operating, air will be fed throughsupply duct 18 and will exit through slits 8 all around the inside ofthe lateral walls of the hood. This additional air can be directeddownwardly or upwardly in any direction by suitably adjusting the airdeflectors 11.

This additional air, when directed substantially towards the center ofthe hood, produces a partial vacuum in the area immediately surroundingthe lower ends of the sides 3 and causes entrainment towards exhaustduct 13, of any smoke or vapor which might have otherwise escaped thehood entirely.

Use of the deflectors 11 in vertical position would deflect a portion ofthe air towards the workmen at the work table for freshening the same inhot weather.

Rotation of louvers 39 will more or less close the openings 41, therebycreating partial vacuum in the spaces between partition 35 and theperforated panels 36, whereby smoke, dust or the like produced on thetable surface will immediately enter the holes of the panels 36 and beexhausted through duct 13.

When louvers 28 of chamber 19 are completely open, the additional airwill be all taken from the room through intake 27, the louvers 26 thencompletely closing the fresh air intake 25. This would be the normaloperation of the air intake and recirculator system 19 in cold weather,in order not to cool the heated room in which the hood 1 and table 4 arelocated.

Depending on the outside weather, the louvers 28 can be adjusted to anydegree of closure, whereby a mixture of air from the room and outsideair will be fed through slits 8, again without unduly cooling the roomair. In hot weather, louvers 26 can be completely closed and theadditional air entirely supplied from fresh air intake 25.

Thus, the system of the invention greatly enhances the efficiency of thehood while maintaining the room in which the hood is located at acomfortable temperature all year round.

FIGS. 3 and show a similar system but as applied against a wall. ln thiscase, the hood 1 has a double wall top 2 and only three double wallsides 3', the hood resting, for instance, against an external wall 14'of the room.

The work table 4 is set against said external wall 14'. The double wallsides 3' are each provided on the inside thereof and near their lowerclosed end with slits 8, each associated with a pivotable air deflector11'.

Two exhaust ducts 13' communicate with the inside of the hood near thewall 14' and are each associated with an exhaust chamber 15' on theoutside of the external wall, each having an exhaust fan 16'.

The hood is further provided with a central air supply duct 18 connectedto the discharge of an air blower located in chamber 19' having a freshair intake together with a room air intake 27' provided with adjustablelouvers 28', as in the first embodiment.

The work table has a perforated panel 36' upwardly extending therefromand diverging from wall 14' and edging 38 of said panel 36' forms anopening 41 with an angle iron 42' secured to the inside ofthe top 2' andextending longitudinally of the hood.

A louver 39', pivoted at 40', is adjustable by manual means for closingmore or less the opening 41'. Here again, additional air is suppliedthrough slits 8' and can be deflected in the required direction by airdeflectors 11, so as to entrain any smoke or vapor which might haveescaped the hood. Also, smoke and vapor can be sucked through the holesof perforatcd panel 36' by partially closing louver 39'.

The additional air supplied through slits 8 or 8 in both embodiments maybe adjusted as to volume by providing a motor 21 for the air blowerhaving different speeds of operation.

P10. 7 shows a hood for a commercial kitchen and for central locationsimilar to the embodiment of FIG. 1. The hood 50 is of double wallformation and exhaust duct 51 opens within a chamber 52 defined by twoconverging filter elements 53 extending longitudinally of the hoodthroughout the length thereof and removably supported by brackets 54 atthe top and 55 at the bottom, said bracket 55 being secured to the hoodtop at suitable intervals by upright posts, not shown, extending withinthe chamber 53.

The filters 52 are preferably washed at intervals with water issuingfrom perforated pipes 56. This water is collected in a drain trough 57having a drain pipe 58.

The hood is otherwise similar to the first embodiment, being provideddownwardly with opening slits 59 and pivotable deflectors 60 forsupplying additional air furnished by a unit, such as unit 19 of thefirst embodiment, and connected to the plenum chamber 61 incommunication with the hollow walls of the hood 50. Deflectors 60 havepreferably edges bent in the same direction.

FIG. 8 shows a hood for commercial kitchens which is applied against awall and which would correspond to the embodiment of FIG. 5. Hood 62shown applied against an external wall 63, is of double wall formation.A plenum 64 is connected with the inside of the top and sides of thehood 62 and connected with the inside of the top and sides of the hood62 and connected in turn with a unit, such as unit 19, to supply freshair or a mixture of room air and fresh air to slits 65 around the bottomedges of the hood, said additional air being deflected in a suitabledirection by air deflector 66. The hood is connected by duct 68 to anexhaust fan system 67 at the exterior of the wall 63 and similar to fansystem 15, l6, 17 of the first embodiment. The exhaust duct 68 is closedby a filter 69, which can be washed by a perforated water pipe 70 andthe water collected by a drain trough 71.

Here again, the additional air supplied through slits 65 will entraintowards the exhaust of the hood any vapors or smoke which might haveotherwise escaped the hood. Moreover, the additional air is supplied atan adjustable temperature in accordance with the adjustment of the airsupply units 19.

FIG. 9 together with FlG. 6 illustrate how the present invention can beapplied to a conventional kitchen hood. The conventional hood 110,provided with filter elements 111 and exhaust fan 112, is located abovethe usual kitchen stove 113.

The system of the invention comprises the usual air intake and air mixerunit 19 supplying additional air through duct 114, also shown in FIG. 6,and extending downwardly and provided with a slit or opening 115. Thelower end of the duct extends along the length of hood and carriesbrackets 116 on which is pivoted a deflector plate 117 having bent edges118 and fully rotatable so as to be adjusted to whatever angle isdesired.

The exhaust duct lower end may be spaced from or adjacent the front endof the hood 110. Obviously, unit 19 and 114 could be arranged to overlie.hood 110, as in other embodiments. Thus, additional air will bedeflected towards the inside of hood 110 entraining any additional vaporor smoke which might have escaped the hood. Also, the additional air canbe used to freshen up the surroundings of the kitchen stove. Here again,the additional air is adjusted as to its temperature due to theadjustable features of unit 19.

lclaim:

1. In a smoke and/or vapor collecting hood, in combination, supply airduct means having an orifice located in the vicinity of said hood, achamber communicating with said duct means, air blower means within saidchamber to discharge air through said orifice, means to direct airdischarged from said orifice into said hood, to assist in theentrainment of smoke and/or vapor into the hood, said chamber having afirst air intake which opens within the room where the hood is located,and a second air intake which opens at the exterior of the room,normally closed louvers in said second air intake for closing the latterand opening only upon suction produced in said chamber by said airblower means and adjustable louvers mounted in said first air intake.

2. In a hood as claimed in claim 1, further including exhaust duct meansin communication with said hood and exhaust air blower means located insaid exhaust duct means.

3. In a hood as claimed in claim 1, wherein said means to direct airdischarged from said orifice into said hood, includes brackets securedto and protruding from said supply air duct means, and a deflector platepivotally mounted on said brackets and disposed opposite said orificeand rotatable through a complete revolution, so as to direct airdischarged from said orifice in any direction.

4. In a hood as claimed in claim 1, wherein said hood is of double wallformation and has a top and sides, said supply air duct means formed atleast in part by the space between the double walls of said hood, saiddischarge orifice located along the lower marginal zone of the sides ofsaid hood, said hood having further an air exhaust duct extendingthrough the top of said hood and opening within the same, and exhaustair blower means located in said last-named duct.

to the air exhaust opening of said hood, a perforated panel alsoupstanding from said work table, defining a space with said wall meansand terminating short of said air exhaust opening to define a passagebetween said hood and panel, and an adjustable closure means in saidpassage to partially close the latter.

